The 30-year-old winger admitted following Oranje's last-16 victory over Mexico last week that he dived during the game to try to win a penalty.

Pinto has now pleaded to those officiating the quarter-final clash in Salvador to "watch Robben closely".

"This is one of the most important questions in the World Cup: diving," the Ticos manager is quoted as saying by Goal.com. "We're really worried about it. I would like the referee and FIFA to watch Robben closely.

"He's one of the three or four best players in the world. I have a website and I analysed him as a player on it; he's amazing. But we have to say that there have been mistakes in this World Cup and we're really worried about Robben's diving, which he admitted. He admitted it!

"So I hope that the officials are very careful tomorrow. I urge them to watch out. We hope that there are no mistakes so, please, I would like to ask FIFA and the officials to watch out and be careful. This is very important and could have a big impact on the result."